Means for holding diamonds during abrasive treatment



0.1. COLEMAN. MEANS FOR HOLDING DTAMONDS DURIVNG ABRASIVE TREATMENT.

APPLICATION FILED JULY 20,1912. 1,329,370. Patented Feb.3, 1920.

IIWEIVTOR rasive Treatment, of which the following is and polishingdiamonds CLYDE J. COLEMAN, or NEW ROCHELLE,

MEN'IS, TO s'mnn-comnan DIAMOND or NEW YORK.

mw xoax,,nssxcnoa, BY vrnsnn ASSIGN- MACHINE COMPANY, me, A conronArroivMEANS FOR HOLDING DIAMONDS DURING ABRAS'IVE TREATMENT,

To all whom it may concern: I

- Be it known that I, CLYDE J. COLEMAN, acitizen of the United States,residing at New Rochelle, in the count of \Vestchester and State of NewYork, liave invented a certain new and useful Improvement in Means forHolding'Diamonds During Aba specification, reference being had thereinto theaccompanying drawings, forming part thereof. v My inventionrelates to the art of cutting or the abrasive treatment thereof, andrelates more particularly to means for holdin the diamond during thecutting and polis ling operations or during the. polishing operation.Objects of my invention are to securely hold the diamond with, exposurefor polishing of all parts above; or below the girdle of the diamond,andto save time in attaching and in releasing the diamond from itsholder, and

to do away, to a large extent, with the skilled manipulation nownecessary in d1amond polishing operations. p The polishing of diamondsas d1st1ngui'shed from that of other precious stones 7 presents peculiardifliculties because of the i considerable heat is polishing operationlextreme hardness of the diamond and because it has to be subjected togreat pres sure. and friction with the result, also, that neratedduringthe eretofore two general means have been employed for holding thediamonds in this device is very to adjwitflo asto diamondduringpolishing. The most common of these is to partially embed the diamond ina of metal in asemi-molten,

state, containe in asmall brass basin or dop, the vdiamond beingmatrixed in and held by the metal "in which it is embedded, after thismetal hasanooled. In polishing way, it is necessary. from time to timeto the holding metal and readjust the diamond in order that a difierentpart thempimaybe exposed for polishing, and it is not possible to ex oseat one time all partsof the diamond a ve or .below its girdle: The,other 'diamondholding means referred to 'consists of a clamp which ispressed against the stone and locked in position, but this clam mg I iSpecification of'Letters Patent. Application filed July 20, 1912. SerialNo. 710,621.

- quent Y readjustment :a' holding held by the cement, this arbor beingcomposed of a refractory material having sub- .mentof the kinddescribed,v an posed of any suitable material g stantially the samecoefficient of expansion Patented Feb. 3, 1920.

the diamond at the correct angle, and'fre is necessary. Many preciousstones other, than diamonds may be held during polishing by ineansof waxor cement, and even diamonds may be so held for the roughing out or.bruting operation,

but not for polishing because of the great pressure required andfriction and heat developed during the polishing of a diamond, the heatthus developed being sufiicient to melt the wax or the diamondcutterscement-used in brutin l I My present invention includes a cementof fully withstand the heat of polishing the diamond and toadhesivelyhold the diamond during the polishing operation, and myinvention also includes a cement for this purpose which hassubstantially thessame coeflicient of expansion as the diamond orsufficient" elasticity heat developed will not loosen the ment, and

the polishing operation diamond from the cemy invention also comprehendsar or to which the diamond is stantially the same coefficient ofexpansion as the cement and diamond.

It is to be'understood that my present invention broadly comprehends adiamond holding, cement, which will hold the dia mond by adhesion andwhich possesses substantially the same coefficient of expansion asthediamond or which will not loosenor deteriorate under the heat ofpolishing, and

. a cement-of this nature may include carbon or may be composed of afusible material,

provided its temperature of fusion is sufiiciently high, such as enamel.My'present g Vc, so that the high such a nature as to be adapted tosuccess- 5 invention further broadly comprehends, in.

combination with a diamond arhorcomhaving subas the cement, goodexamples of such materials being carbon, porcelain, 'glass, quartz, etc;The broad invention of the cement and arbor is broadly claimed hereinand the carbonaceous cement and carbon arbor are more specificallyclaimed herein, while the jnsiblefcement, such as above indicated, is

holding ce-,

broadly and specifically claimed in another application filed on evendate herewith, Se.- rial Number 710,622.

\Vhileuny,present invention is directed more particularly to obtaining asatisfac' tory solution of the peculiarly difficult problem of holdingdiamonds during the polishing operation, it also presents a distinctadvantage in that it1may be employed to hold the diamonds during thepreceding operation of cutting or bruting, thereby doing.

away with the present necessity of transferring the diamond from theholding means employed for bruting to the other different holding meansemployed for polishing, involving the necessity of re-centering thediamond. Therefore, in the practice of my invention, I may cement therough or uncut diamond-to an arbor embodying my invention by means of acement embodying. my invention, and first brute or rough out the diamondin any suitable way, for example, in a lathe, and then takethis samearbor, with the bruted diamond attached, and put it into a holdin deviceand polish the diamond, without t ie necessity of having to transfer thediamond to another arbor.

I shall now describe my invention with reference. to the accompanyingdrawing illustrating one embodiment thereof, and

shall thereafter point out my invention in claims.

The drawing is 'an elevation, partly in vertical section, of a diamondholder embodying my invention.

The diamond 1 has previously been roughed out or bruted to asubstantially regular rounded form. The bruted diamond is shown as heldtothe cupped end of a c; -bon arbor 2 by means of a body of carbonaceouscement 3. This cement will not be softened by the heat of polishing thedian'iond and, because of the fact that the cement 3 and the arbor 2have substantially the same coefficient of expansion as the dia mond 1,the expansion of the diamond under the heat of polishing will not loosenit from the arbor.

The carbon stick or arbor 2 may be of the same composition as the wellknown electric are light carbons. The carbonaceous cement 3 may becomposed of powdered coke. rye flour and gum shellac, or may be of othersuitable composition. This cement maybe made by all of the ingredientsbeing ground and masticated together with water or thin molasses.Another formula and suitable proportions of the ingredients thereof is75 parts finely powdered anthracite coal, 25 parts finely powdered gumshallac, 50 parts boracic acid, parts chlorid of magnesium or chlorid ofcalcium and a suflicient solution of carameled cane sugar to make thewhole into a stiff paste. Instead prising a diamond-holding adhesivecement having resistance to heat above the temof the cane sugar, thoughless suitable, a solution of coal tar may be employed as a carbonaceousbinder. In attaching the diamond 1 to the arbor 2 with this cement, thecement is applied cold and baked at a high temperature for thirtyminutes out of contact with the air, to carbonize the cement so that thediamond will be held by adhesion. To remove the diamond 1 from the arbor2, the diamond is snipped off with a pair of cutting pliers.

The arbor 2 i tapered, as shown in the drawing, and is inserted inacorrespondingly flared bore in a dop' head 4 provided With a tubularshank The arbor 2 may be loosened from the dop head 4 when desired byturning a thumb screw 6 screw-threaded into the outer end of the shank5, this screw being provided with a stem 7 extending withinthe' bore ofthe shank 5 and adapted to push out the arbor'2.

The other parts of the diamond-holding tool'may be of any suitableconstruction and the holder illustrated in the drawing is of a usualconstruction and its operation Will be readily understood withoutthenecessity of a particular description of those parts which do notdirectly relate to the present invention. The diamond 1 is shown as heldin position for polishing on a lap 8, a portion only of which isillustrated in thedrawm It is'obvious that various modifications may bemade in the construction shown in r the drawings and above particularlyde- 100 scribed within the principle and scope of my invention.

I claim:

1. Means for holding a diamond comhaving resistance'to heat abovethe'temperature produced in diamond polishing, and an arbor havingsubstantially the same co'eificientof expansion as the cement and towhich the cement is attached by adhesion to hold the diamond on thearbor.

2. Means for holding a diamond comprising an arbor, and a carbonaceouscement for holding the diamond to the arbor.

3. Means forholding a diamond comprising a carbon arbor, and acarbonaceous cement tor holding the diamond to the arbor.

4. Means for holding a diamond comprising a diamond-holding adhesivecement perature produced in diamond polishing and also havingsubstantially the same coefliicient of expansion as the diamond, and anarbor having resistance to heat above the. temperature produced 'ndiamond polishing and also having substantially the same coefiicient ofexpansion as the cement and to which the cement is attached by adhesionto hold the diamond on the arbor.

5. Means for holding a diamond comprising an arbor, and a carbonaceouscement for holding the diamond to the arbor, the cement includingcarbon, a resinous substance, a boron compound, a mineral salt and acarbonaceous binder.

(3. Means for holding a diamond comprising an arbor, and a carbonzueouscement for holding the diamond to the arbor, the cement includingcarbon, a boron compound, a mineral salt and a carbonaceous binder.

7. Means for holding adiamond comprising an arbor, and a carbonaceouscement for holding the diamond to the arbor, the cement including aboron compound, a mineral salt and a carbonaceous binder.

ing, and having substantially the same coctlicient of expansion as thediamond, and an arbor for holding said body.

In testimony whereof I have aflixed my signature in presence. of twoWitnesses.

CLYDE J. COLEMAN.

\Vitnesses:

WM. ASHLEY KELLY, VICTOR D. Bonsr.

